1. Technical Field
The present invention relates to a piezoelectric driving device, a motor, a robot, and a pump.
2. Related Art
A piezoelectric actuator (piezoelectric driving device) which vibrates a vibrating body by a piezoelectric element and drives a driven body is used in various fields since a magnet or a coil is not necessary.
In the piezoelectric driving device, it is described that a spring region is provided in the vicinity of a contact portion between the piezoelectric driving device and the driven body in order to prevent excessive vibration, to prevent point contact between an ultrasonic vibrator and a driven body member, and to improve power efficiency (for example, refer to JP-A-2008-295234, JP-A-6-22565, and JP-A-2015-80329).
However, in JP-A-2008-295234, JP-A-6-22565, and JP-A-2015-80329, only qualitative properties, such as the presence of the spring region, are described, and a spring constant of a specific spring region or a deformation amount of the contact portion due to pressing, is not mentioned.